Patent application number | Description | Published |
20130083866 | DISTORTION COMPENSATOR AND DISTORTION COMPENSATION METHOD - A distortion compensator compensates for distortion of a signal caused by an amplifier. A storage section stores a plurality of compensation coefficients used for distortion compensation. A selection section selects a compensation coefficient corresponding to an index value indicative of a power level of the signal from among the plurality of compensation coefficients. The selection section determines whether or not the power level is higher than a threshold, and uses, based on a determination result, a first index value calculated without using a logarithmic operation or a second index value calculated by using a logarithmic operation. | 04-04-2013 |
20130084810 | RECEIVING APPARATUS, BASE STATION APPARATUS AND METHOD FOR REDUCING INTERFERENCE WAVE - A receiving apparatus includes: an interference wave reducer configured to reduce an interference wave included in a received signal; and an automatic gain controller configured to automatically control a gain for the received signal, the automatic gain controller including a convergence time saver to save convergence time of an automatic gain control for the received signal based on an input of an interference wave. | 04-04-2013 |
20130259154 | WIRELESS APPARATUS AND DISTORTION COMPENSATING METHOD - A wireless apparatus includes amplifying systems each including a storing unit storing a distortion compensation coefficient for compensation for a nonlinear distortion of one or more transmission signals, a compensator compensating for the nonlinear distortion using the distortion compensation coefficient stored in the storing unit, and an amplifier amplifying the transmission signal after distortion compensation. The wireless apparatus further includes a switch that selects feedback signals corresponding to the transmission signals output from the amplifying systems, a subtractor that derives one or more differences between the feedback signal selected in the switch and the transmission signal, a first calculator that derives a distortion compensation coefficient that restricts the difference derived in the subtractor, and a switch controller that controls a length of time during which the feedback signal is selected in the switch depending on magnitude of distortion of the transmission signal output from the amplifying system. | 10-03-2013 |
20130321078 | DISTORTION COMPENSATION APPARATUS AND DISTORTION COMPENSATION METHOD - A distortion compensation apparatus including: a processor configured to generate a pre-distortion signal by compensating an input signal for a distortion based on a distortion compensation coefficient and a plurality of delayed signals obtained by delaying the input signal by a plurality of amounts of delay, and an amplifier configured to generate an amplified signal by amplifying the pre-distortion signal, wherein the processor calculates the distortion compensation coefficient based on the input signal, the pre-distortion signal, and the amplified signal, and calculates the plurality of amounts of delay based on the amplified signal. | 12-05-2013 |
20140003554 | DISTORTION COMPENSATING DEVICE AND DISTORTION COMPENSATING METHOD | 01-02-2014 |
20140106692 | TRANSMISSION APPARATUS, OUTPUT CONTROL METHOD FOR TRANSMISSION APPARATUS AND TRANSMISSION SYSTEM - A transmission apparatus includes: an amplifier configured to amplify a transmission signal; a calculation unit configured to calculate a standing-wave ratio based on the transmission signal and a signal from an antenna to the amplifier; and a controller configured to switch a state of the amplifier based on the state of the amplifier and the standing-wave ratio. | 04-17-2014 |
20140145788 | DISTORTION COMPENSATION DEVICE AND DISTORTION COMPENSATION METHOD - A distortion compensation device includes a storage unit, an address generator, and a distortion compensation processor. The storage unit stores therein a distortion compensation coefficient for compensating distortion generated in an amplifier for amplifying an input signal. The address generator generates a first address based on a power value of the signal at a current time. Furthermore, the address generator delays, every time a new augend is input, the sum of the power value of the signal at the current time and the augend. The address generator generates a second address based on the sum obtained by calculating a new augend, from the delayed sum. The distortion compensation processor acquires a distortion compensation coefficient corresponding to a combination of the first address and the second address from the storage unit and performs distortion compensation processing on the signal by using the acquired distortion compensation coefficient. | 05-29-2014 |
20140146910 | DELAY QUANTITY ESTIMATION APPARATUS AND DELAY QUANTITY ESTIMATION METHOD - A delay quantity estimation apparatus comprises a first correlation value arithmetic unit to calculate a first correlation value as a correlation value between a first input signal and a feedback signal delayed with a first delay value; a second correlation value arithmetic unit to calculate a second correlation value as a correlation value between the first input signal and a feedback signal delayed with a second delay value; and a delay quantity estimation unit to estimate a delay quantity of the feedback signal with respect to the input signal on the basis of the first difference value as a difference between the first correlation value and the second correlation value, wherein the second delay value is a value given by adding a certain value to the first delay value. | 05-29-2014 |
20150077180 | DISTORTION COMPENSATION APPARATUS AND DISTORTION COMPENSATION METHOD - A distortion compensation apparatus includes: a storage unit that stores a distortion compensation coefficient; a distortion-compensation-coefficient selecting unit that takes a logarithm of power of an input signal and exponentiates a value obtained by taking the logarithm, and that selects a distortion compensation coefficient that is stored in the storage unit according to a value obtained by the exponentiating; a distortion-compensation processing unit that acquires the selected distortion compensation coefficient from the storage unit, and that performs distortion compensation processing on the input signal to the distortion-compensation-coefficient selecting unit using the acquired distortion compensation coefficient; an amplifier that amplifies the signal subjected to the distortion compensation processing; and a distortion-compensation-coefficient updating unit that updates the distortion compensation coefficient stored in the storage unit based on the amplified signal and the input signal to the distortion-compensation-coefficient selecting unit. | 03-19-2015 |